Ascochlorin, a new antibiotic, found by the paper-disc agar-diffusion method. I. Isolation, biological and chemical properties of ascochlorin. (Studies on antiviral and antitumor antibiotics. I).

A new antibiotic, ascochlorin, C23H29O4CI, was obtained from the filter cake of the fermented broth of Ascochyta viciae Libert. Ascochlorin inhibits plaque formation of both DNA and RNA viruses in the agar-diffusion plaque inhibition method. However, it showed no antiviral activity by the tube culture method. It showed cytotoxicity to chick embryo fibroblast monolayer and HeLa cells at a concentration of 0.3 meg/ml in tube culture. The anti biotic was obtained in two forms, the physical and chemical properties of which are described.